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H. A. HOESCHEN.

AUTOMATIC ELECTRIC SWITCH.

APPLICATION FILED N.0V.22,1918'.

1 ,3 1 6,305 Patented Sept. 16, 1919.

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i i, HENRY A HOESCHEN. Q/vi tvwoo;

H. A. HOESCHEN.

AUTOMATIC ELECTRIC SWITCH.

APPLICATION FILED NOV. 22,1918.

1 316,305, PatentedSept. 16, 1919.

2 SHEETSSHEET Z.

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HENRY A. Hozscuzu.

attouwiw UNITED sirrrrns- A E T OFFICE.

HENRY A. nonscnmr, or organs, unnnnsxmnssmnon or own-mu 'ro BAKER ICEMACHINE 001mm,;or omens, NEBRASKA, A CORPORATION or NEBRASKA. I

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Specification of Letters Patent. Patentd Sept, 16, 1919.

I Applicationfiled liove nber 22, 1918. Serial No. 263,930.

I To all whom/ct may concern} l Be it knownthatL'HENRrA. HoEsonnN,

a citizen of the United States, and a resident of Omaha, in the countyof Douglas and State, of Nebraska, have invented certain 'MY inventionrelates to' el y actu' 10- matically, to sto and start the motor or to 4stop and start t e operation of other electrically-operated devices inaccordance with conditions which are Vfil'ld' b the operation of themotor or the like. l huawhere an electric motor is employed to operate acom pressor for a refrigerant, it. may, be desirable to stop and startthe-motor automatically according to decreases and increases oftemperature 1n a refrigerating chamber which is cooled by the compressedrefrigerant. The main switch providedby my invention is actuated byelect'romagnets or solenoids'which are energized alternately byelectrical energy supplied thereto by control-circuits, the latter beingcontrolled by a thermostat or the like, and the control-circuits beingopened at theends of movements of the main switch, after being closedfor a sufiicient time to efi'ect the actuation of the main switch. It isthe object of my invention to provide actuating means for the mainswitch whereby the same is locked inboth open and closed againstmovement by any force other than that of the actuating means itself; toprovide means for opening the control-circuit only after the main switchhas been fully moved in either direction, whereby the full force oithe'solenoids or electroinagnets is available for actuating the mainswitch; and in general to provide an inexpensive, durable, efiicient andconvenient mechanism of this character.

In the accompanying drawings, Figure 1 is a front view of a switchmechanism'embodying my invention, Fig. 2 is a diagram- Bil maticviewillustrating-the electrical circuits of a possible application of theswitch mechanism, 3 is a front view of the switch mechanism in closedposition, one of the actuating solenoids being in axial section, Fig. isa detail section on the line ii of Fig.

1ron, having foot-portions. 1 v uporr and. are secured to the base-plate8.

material such as' brass said sleeve 3, Fig. 5 is. a detail sectionon theline 5--'5 of Fig, 3, Fig. 6 is a detail side view of the mainswitch-lever, a portion of the base being in section, and Fig.' 7 is adetail view of one of the contact-posts.

In carrying out my invention according t the illustratedembodiment-thereof, I provlde a base-plate 8 of insulating material, onwhich there is mounted a pair of soleside noids A and B, extendinghorizontally and y in axial alinement with each other. Each so'lenoidhasa pair of end-plates 9 and 10, preferably of magnetic materi 1 such assoft which rest Said end-plates are connected to each other by a sleeve12,;preferably of non-ma ttin over a tubular 13 on the plate 9, an

passing through a central aperture in the plate 10. The end-plates andsleeve thus form-a spool, which is suitably insulated and has a coil 14:wound thereon, the terminals of the. coil being connected withbinding-V:

etioposts 15 on the base 8. 'Tubular cores 16 fit slidably within thesleeves 12 of the solenoids, and said cores are loosely connected toeach other'by means of rods 17 formed internally with and extendinoppositely from the-ends of a plate 19. %he portions of said rodsadjoining the plate are of smaller diameter than the bore of the cores16,

but the ends of the rods have heads nearly, aslarge as the bore, andsaid heads areconnected with-the cores by transverse pins 18 of whichthe ends fit in short slots in the sides of the cores. By the describedconnections a slight movement of either core may occur without movingthe other core or the plate 19, and binding of the cores in the sleevesis avoided, even should the sleeves not 'bein perfect alinement witheaclr other. The plate 19 has a cam-slot formed 33 extending parallelwith the 'axis of the solenoids, but oppositely displaced laterally fromsaidaxis, and an intermediate ogeecurved portion 3% connectingsaid-end-portions 33. One edge of the cam-plate l9 bear against a roller36 which is mounted revolu'bly upona post 37 secured on the baseplate 8by a screw 38 extending through from the back of the base-plate as shownin Fig. 5

therein, said slot comprising end-portions by the arm 22.

The main switch-lever has three arms, 20, 21 and 22, and is mountedpivotally upon a stud 23 secured on the base-plate. Blocks 24 ofinsulating material are secured to the arms 21 and 22 by means of screws25, and said blocks carry laminated brushes each comprising a series ofcurved resilient metal -plates 26, having the end-portions thereoflongitudinally kerfed or slitted, as shown in Fig. 6, to thereby form aplurality of resilient contact fingers. A pair of contactposts 27 and 28are arranged to be engaged by the brush carried by the arm 21', and ament of those following. Opening movement of the switch-lever is limitedby an adjusta'ble stop formed by a screw 29 carried on a post 30arranged on the base-plate 8, as shown.

The arm 20 of the switch-lever extends alongside the cam-plate 19,contacting slidably therewith, and having an extended footportion .35which engages the plate so as to prevent any tendency thereof to tilt orrotate about the axis of the rods 17. A roller 32 is mounted revolublyon a pin or stud 31 carried by said lever-arm 20, and said roller workswithin the cam-slot 1n the plate 19. By alternate energization' of thesolenoids A and B, the cores 16 and cam-plate 19 are moved to actuatethe switch-lever between the open and closed positions, shownrespectlvely in Figs. 1 and 3, the movement of the lever being madewhile the roller 32 is traversing the ogee-curved intermediate portion34 of the cam-slot, and the lever being held stationary during such timeas the roller is in the end-portions 33 of the cam-slot.

At one edge of the cam-plate there is a projecting insulated pin 48which is employed to operate circuit-breaking devices for opening thesolenoid-circuits at the conclusion of the movements of the cam-plate.On the base-plate 8 near the solenoids there are mounted a pair of posts39 and 46 of which the end-portions are slotted to receive resilientcontact-fingers 41 and 45, respectively, said fingers being retained inthe slots by screws.40. The adjacent ends of the contact-fingers 41 and45 are slitted as indicated in Fig. 4, and the ends of the fingers tendto engage a contact-plate 42 carried by a post 43 which is secured tothe base at a position intermediate the posts 39 and 46. Each of thecontact-fingers have a bowed portion 47 presenting inclined surfaces forengagement-with the pin 48 carried by the cam-plate. The arrangement issuch that, at each end of themovement of the cam-plate, and after theroller 32 has passed from the curved intermediate portion of thecam-slot into the axially extending end-portions 3.3 of said slot, thepin 48 will engage one of the portions 47 and press the respectivecontact-finger out of engagement with the plate 42.

Electrical connections between the Various parts are formed byconductors arranged on the back of the base-plateS, and indicated bydotted lines in Fig. 1, as follows: From the terminals of the solenoid Aat the binding-posts 15, connections are formed to the post 39 carryingthe contact-finger 41, and to a binding-post 49 disposed near the edgeof the base-plate. From the terminals of the coil B similar connectionsare formed with the contact-finger 45 and a bindingpost 51. The post 43which carries the plate 42 is connected with a binding-post 50, and themain-switch contact-posts 27, 28,27 and 28 are connected respectivelywith bindingposts 52, 53, 54 and 55 mounted on the baseplate as shown.

Referring to the circuit-diagram in Fig. 2, there are represented, inaddition to the parts of the switch mechanism proper, an electricalgenerator G, a motor M, and a thermostatic switch or circuit-closer T,the latter comprising a central member or contact-arm 56 movable betweenstationary contacts 57 and 58. It may be assumed, as before mentioned,that the motor actuates a compressor for supplying a refrigerant to coola room or chamber in which the thermostat T is located, and that it isdesired to start the motor automatically when the temperature in thechamber reaches a determined maximum,- and to stop the motorautomatically when the temperature has been reduced to a determinedminimum. The main circuit from the enerator to the motor is indicated int e diagram by heavy lines, and passes through the main-switch contacts27, 28, 27 and 28. The controlcircuits in the arrangement shown aresupplied with energy from the same generator, one of the supply wiresbeing connected with the center contact 42 of the circuit-breakingdevice or control-switch, and the other supply wire being connected withthe central member 56 of the thermostat. One terminal of the solenoid A,as from the binding-post 49, is connected with the thermostat-contact57, and one terminal of the solenoid B, as from the binding-post 51, isconnected with the thermostat contact 58, the other terminals of thesolenoids being connected respectively with the contact-fingers 41 and45 of the control-switch. as before noted. The parts being in thepositions indicated in full lines, which correspond with the positionsof the switch mechanism shown in Fig. 1, the motor-circuit is open andboth control-circuits are open, but the circuit through the solenoid Bis closable by movement of the thermostat-member 56 to engage thecontact 58. Upon closing of said control-circuit and energization ofsaid solenoid, the switch-mechanism is moved to the positions indicatedby dotted lines in Fig. 2 and shown fully in Fig. 3, at whichthemain-switch is closed and the controlcircuit through the solenoid'B isbroken by the disengagement of the contact-finger 45 from the plate 42.At the same time the contact-finger 41 is engaged with the plate 42, sothat the control-circuit through the solenoid A is closable by movementof the thermostatmember 56 to engage the contact 57 It will be obviousthat by the described actuating means for the main switch-lever, saidleveris locked in either the closed or open position when the roller 32lies in the end-portions 33 of the cam-slot, and no movement of theswitch-lever can occur unless the cam-plate is moved by the solenoids.It will be noted also that the form of the intermediate portion 34 ofthe cam-slot is such that the movement of the lever is most rapid at anintermediate portion of its travel, andthat the rate of movement 1sreduced at the ends oftits travel, thereby making the work of thesolenoids eas er, particularly at the end of the switch-closlngmovement, where it is necessary to cause bending of the laminatedbrushes 26. When the switch is closed the reaction of the brushesagainst the lever causes a downward pressure of the roller 32 upon thecam-plate, but most of the lateral pressure is recelved from thecam-plate upon the guide-roller 36, so that movement of the cam-plate 1snot materially retarded by lateral pressure upon the solenoid cores,

Now, having described my invention, what I claim and desire to secure byLetters Patent is:

1. In an automatic electric switch, a pivoted main switch-lever,actuating means movable reotilinearly adjacent to said switch-lever, aplate carried by said actuating means and having therein a cam-slotcomprising laterally offset end-portions extending parallel to the lineof travel of the actuating means and an intermediate portion extendingangul-arly to said line of travel, and a member carried by theswitch-lever and entering said cam-slot, said parts so arranged that theswitch-lever is moved about its pivot by movement of the plate whilesaid member is in the intermediate portion of the camslot, and movementof the switch-lever prevented by said member when the same lies in theend-portions of the cam-slot.

2. In an automatic electric switch, a pivoted main switch-lever, a pairof solenoids axially alined and having movable cores, a

. ted

cam-plate disposed intermediate said cores. and connected looselytherewith, said camplate having a slot with an intermediate portionextending across the axis of the cores I and end-portions extendingparallel to said axis, a portion of the main switch-lever lying insaidslot so as to traverse the intermediate portion of the slot and beactuated about the pivot of the lever by rectilinear movement of theplate, a control-switch having members connected in circuits through thesolenoids/and means carried by the camplate and arranged to actuate thecontrolswitch at the conclusion of movements of the main switch-lever.

3. In an automatic electric switch, apair of solenoids having movablecores, 9. switchactuating member connected with said cores and movablethereby rectilinearly in alternating directions, ,a pivoted switch-leverhaving a part engaged by said actuating member and movable therebyduring an intermediate portion of the travel of said member,control-switches connected in circuits through the solenoids, and meanson the actuating member for opening the ,con-

-trol-switch for each solenoid at the conclusion of the movement of themember efi'ected by energization of the, respective solenoid.

4:. In an automatic electric switch, a pair of axially alined solenoids,cores slidable therein, a switch-actuating member loosely connected withand carried by said core member also arranged to lock the mainswitch-lever in circuit-closing and circuito-pening position at theconclusion of the respective movements. v

5. Mechanismas specified in claim 4:, in which the switch-actuatingmember comprises a cam-slotted plate, and the main switch-lever ispivotally mounted and has an arm extending adjacent to saidcam-slotplate and movable transversely of the path of travel of saidplate.

6. Mechanism as specified in claim 4, in which the switch-actuatingmember comprises a cam-slotted plate, resilient brushes carried bythemain switch-lever, fixed contacts engageable by said brushes at thecircuit-closing position, and a guide-roller arranged to receive thelateral pressure from the cam-slotted plate resulting from reactivepressure of the resilient brushes upon the extending alongside thecam-plate and movswitch-lever when the same is inv circuitabletransversely of the path of travel of closing position. said plate-saidarm contacting slidably with 10 7. Mechanism as specified in claim 4, inI one side of the plate and adapted to prevent 5 which theswitch-actuating member c'omtilting thereof.

prises a, cam-plate, the main switch-levei pivotally mounted and havingan arm HENRY A. HOESCI-IEN.

